A land grid array (LGA) electrical connector according to the prior art is used to electrically connect a chip to a circuit board, and is applied extensively to high-frequency and high-speed transmission devices, and has superior electrical conduction properties. However, with the increasing of the chip's transmission rate, the number of pads set on the chip increases accordingly. Under a certain constraint on the chip's volume, it is unavoidable to reduce the area or the width of a single pad. Consequently, the LGA electrical connector according to the prior art cannot satisfy the requirements imposed by the development of the chip any longer.
FIG. 1 shows a cross-sectional view and a partially enlarged view of an LGA electrical connector (a) according to the prior art while connecting to a chip. The LGA electrical connector (a) is electrically connected to a chip (b) having a plurality of pads (b1) and comprises a base (a1) and a plurality of terminals (a2) obliquely disposed in the base (a1). The base (a1) includes a first sidewall (a11), a second sidewall (a12) facing to the first sidewall (a11), and a receiving space (a13). While being used, the chip (b) is disposed in the receiving space (a13), and the pads (b1) contact the terminals (a2) correspondingly. In order to align precisely, the gaps between the chip (b) and the first sidewall (a11) and between the chip (b) and the second sidewall (a12) are small. While the chip (b) being pressed downward, the pads (b1) press the terminals (a2). The terminals (a2) move with respect to the pads while being pressed and thus scrape against the pads for removing grime thereon.
Although the electrical connector described above has the benefit of removing grime by scraping between the terminals and the pads, it still has a drawback. Under a certain downward press on the chip, the horizontal displacement of the terminals with respect to the pads is fixed. Given the fixed horizontal displacement, if the area or width of the pads shrinks, the terminals will definitely go beyond the pads and cannot be controlled within the area of the pads. Consequently, the electrical connector cannot connect to the chip normally.
Accordingly, it is necessary to design a novel electrical connector for solving the problem described above.